Loading arms are usually used to load and unload fossil fuels such as crude oil, gasoline, light oil, and natural gases (LNG and LPG) between fossil fuel transport ships and storage tanks on the land. A general loading arm includes, as a support structure, an outer riser erected on the land, an inboard boom pivotally supported on the top portion of the outer riser, an outboard boom having an upper end portion pivotally connected to the upper end portion of the inboard boom, a counterweight mounted on the lower end side of the inboard boom, and the like.
The loading arm also includes, as a fossil fuel transport tube, an inner riser disposed in the outer riser, an inboard arm connected to the inner riser through a swivel joint and disposed on the inboard boom, an outboard arm that has an upper end portion connected to the upper end portion of the inboard arm through the swivel joint and is supported by the outboard boom, an emergency release system (ERS) connected to the lower end portion of the outboard arm through the swivel joint, and a joint portion connected to the ERS through or not through the swivel joint.
A loading arm is also used to transport fossil fuel between a storage tank on the land and a tank track.
Patent literature 1 discloses a loading arm that is used to transport LNG or the like between a tank track and a storage tank, and uses a single-tube flexible pipe. This loading arm includes a gantry, an inboard arm supported on the gantry, an outboard arm connected to the distal end portion of the inboard arm, a rotary joint connected to the lower end of the outboard arm, a track connecting arm supported by the rotary joint, and a flexible pipe for the transportation of LNG or the like, which is disposed in a space above the inboard arm and the outboard arm, has a top portion supported on a flexible base of a connecting portion between the inboard arm and the outboard arm, and has a distal end portion supported on the distal end portion of the track connecting arm.